Rotational endoscopic mechanism with jointed drive mechanism

ABSTRACT

Described herein is an endoscopic instrument such as a dissector, scissor or grasper in which there is provided a shaft which defines a longitudinal axis of the instrument. This shaft is able to rotate about the handle portion of the instrument. This mechanism also provides for articulation of the end effectors with respect to the longitudinal axis of the shaft. This articulation is accomplished by causing angulation of the end effector with respect to the shaft. Because driving the cable is accomplished around any such angle, the end effectors continue to be able to operate. There is disclosed herein a locking mechanism which allows the rotational aspect of the device to operate to rotate the entire articulating mechanism.

FIELD OF THE INVENTION

Generally, this invention relates to endoscopic mechanisms. Morespecifically, this invention relates to endoscopic mechanisms such asgraspers, dissectors, and scissors, wherein the device is capable ofrotating. Most specifically, this invention relates to such mechanismswherein while the device may rotate around the longitudinal axis of theinstrument, the end portion of the shaft is also able to angulatethrough an articulation, such that the shaft may move from 0° to a 90°angle with the shaft.

BACKGROUND OF THE INVENTION

Within endoscopic surgery, there is a recognized need for simple devicessuch as graspers, dissectors, scissors, and other basic surgicalinstruments. These instruments are necessary in order to perform simplefunctions during the endoscopic procedure. Specifically, devices such asgraspers are necessary in order to properly move the work site away fromthe other vital organs so that the tissue to be worked on may beisolated and surgery may be performed. Scissors may be needed in orderto make an appropriate cut in tissue, muscle or other vasculature.Dissectors can be necessary to separate one portion of tissue fromanother. These instruments also enable the other, larger instrumentssuch as staplers and ligating clip appliers to have enough volumetricroom in order to perform operations such as appendectomies,cholecystectomies, herniorrhaphies, etc.

Traditionally, instruments such as graspers, dissectors, scissors andother endoscopic instruments have been mounted on generally straightshafts. These shafts may or may not have been able to rotate about thelongitudinal axis of the shaft. Nonetheless, there has been perceived aneed for the end effector of the shaft to be able to angulate withrespect to the longitudinal axis of the shaft. This may enable thesurgeon to attack the tissue which is to be operated from an obliqueangle. In fact, it may be desirable to have the shaft angulate up to 90°with respect to the longitudinal axis of the shaft. In many ways, thisfunction can be analogized to the capability of the human hand to rotatearound the "axis" of the arm, and also "angulate" about the wrist. Ofcourse, while the hand is able to function with pure rotation, thedegrees of freedom given by wrist action are much greater and in manyways enhance the ability of the hand to perform simple daily functions.Thus, there is perceived a need for an articulating, angulatingendoscopic instrument so that the functions of such mechanisms can bemade much more versatile.

Previously, there have been attempts at creating articulatinginstruments, but none of these instruments have the capability ofperforming functions at an angulation of 90° to the longitudinal shaftof the endoscopic mechanism. This is due, in large part, to thetolerancing and material strength problems encountered by themanufacturers of such instruments. It must be remembered that it isnecessary to not only have an instrument which can create suchangulations, but it also be capable of operating the end effectors atsuch angulations. This combination has been difficult to create, and hascaused design sacrifices to be made. Generally, these sacrifices havebeen made to the versatility of such instruments, so that suchendoscopic instruments are not capable of being angulated at 90° to theshaft of the instrument. Of course, with this restrictive limitation,the ultimate capabilities of such angulations are not met.

SUMMARY OF THE INVENTION

Described herein is an endoscopic instrument such as a dissector,scissor or grasper in which there is provided a shaft which defines alongitudinal axis of the instrument. This shaft is able to rotate aboutthe handle portion of the instrument. Such rotation also causes rotationof the end effectors, such as the scissors and graspers placed at theend of the instrument. Such rotation is effected by a rotating knobplaced toward the handle portion of the instrument. The operation of theinstrument in order to accomplish grasping and cutting and the like isaccomplished by the scissor-like motion of a pair of handles located atthe rear of the instrument. One handle is fixed relative to the driveshaft. The other handle is capable of pivoting with respect to thelongitudinal axis of the shaft. This rotation causes a sliding motion ofa drive shaft contained within the outer tube of the mechanism. Thesliding motion of such drive portion is able to operate a flexiblecable. This flexible drive cable moves with relation to a clevis, whichcauses operation of the end effectors contained in such a mechanism. Inthis way, operation of the mechanism is accomplished, allowing thesurgeon to maintain a stationary hand position.

Importantly, this mechanism also provides for articulation of the endeffectors with respect to the longitudinal axis of the shaft. Thisarticulation is accomplished by causing angulation of the end effectorwith respect to the shaft. Articulation is generated by use of aarticulating knob which causes a helical screw to exert a relativemotion on a winged nut attached to an articulation tube contained in themechanism. With motion of this drive screw, the articulation tube iscaused to move with respect to both the outer tube of the mechanism andthe drive shaft. By causing this relative motion, the articulation tubecauses a hinged joint to move relative to the outer tube of themechanism. This joint causes the end effector to angulate with respectto the longitudinal axis of the outer tube. Depending upon the amount ofarticulation created by the articulation knob, the outer shaft willangulate from 0° to 90° with respect to the outer shaft of themechanism.

Naturally, once the mechanism has articulated, it is important that thedevice continue to be able to operate. This is accomplished by acable-type mechanism which is capable of operating the shaft and its endeffectors around the angle created by the articulated angulation.Because driving the cable is accomplished around any such angle, the endeffectors continue to be able to operate. In this way, use of the devicecan be made at any angle between 0° and 90° with respect to thelongitudinal axis of the shaft.

Finally, there is disclosed herein a locking mechanism which allows therotational aspect of the device to operate to rotate the entirearticulating mechanism. In this way, during rotational motion,articulation is locked in place, and there is no articulation of the endeffector with respect to the longitudinal axis of the shaft. Incontrast, during articulation, the rotational mechanism is locked inplace so that relative rotational position is maintained. This"clutch"-type mechanism allows the user to accomplish many variedfunctions during an endoscopic procedure. Utility is maintained, and theenhancements created by this articulated angulation continue to berealized.

This new invention will be better understood in relation to the attacheddrawings taken in conjunction with the detailed description of theinvention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an endoscopic instrument of thisinvention;

FIG. 2 is a exploded assembly view of the end effector portion of theinstrument of this invention;

FIG. 3 is an exploded assembly view of the handle portion of the presentinvention;

FIG. 4 is a perspective view of the articulated end of the instrument ofthis invention; and

FIG. 5 is a cross-sectional view of the handle portion of the instrumentof this invention taken across lines 5--5 of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

A device 1 for performing endoscopic procedures is described herein, andisseen generally in FIG. 1. This device 1 is capable of rotating aboutthe shaft or outer tube 10 of the mechanism. As well, this device 1 iscapableof being angulated so that the end effector portion 100 of themechanism may be placed at an angle up to 90° with respect to thelongitudinal axis formed by the shaft of the mechanism, as better seenin FIG. 4. Each of these functions will be described herein.

As better seen in FIG. 2, there is described a drive rod 30 which isgenerally cylindrical and runs for the entire length of the instrument.This drive rod 30 is capable of being placed within an articulation tube20. The articulation tube 20 is also cylindrical and is able to be movedlongitudinally with respect to the drive rod 30. Further, thearticulationtube 20 and the drive rod 30 fit within the outer tube 10 ofthe mechanism.

The driving portion of the mechanism and its end effectors will now bedescribed. The drive rod 20, as has been previously explained, iscapable of moving in a sliding direction with respect to the outer tube10. This drive rod 30 is connected to a drive cable 50 at crimp 32 atthe distal end of the drive rod 30. This drive cable 50 fits securelywithin a cable sleeve 140. At the distal portion of the drive cable 50,there is attacheda rod end 101 at crimp 102. This rod end 101 is capableof generating the functions of the particular mechanism. The rod end 101is held within the longitudinal center 42 of clevis 40. The drive cable50 also fits securelywithin the center 42 of the clevis 40 and both therod end 101 and drive cable 50 are capable of moving with respect to theclevis 40.

When the drive cable 50 is moved with respect to the clevis 40, itguides the rod end 101 in a longitudinal fashion with respect to theclevis 40. In so doing, the rod end 101 is capable of pivoting the pairof jaw links 80. These jaw links 80 rotate about the rod end 101 atpivot points 103 connected to flared ends 82 so that jaw links 80 flareoutwardly from the axis created by the drive rod 30 and the drive cable50.

At the distal end of the rod links 80, are attached the end effectors ofthe instrument. For instance, in this example, there are shown endeffectors which comprise upper jaw 60 and lower jaw 70 of a graspingmechanism. However, it is to be understood that these end effectors maybescissors or dissectors or other endoscopic instruments. What isnecessary is that the end effectors 60, 70 are attached at theirrespective proximalend 62,72 to the distal ends 84 of the jaw links 80,in order that the jaw links 80 may guide motion of the end effectors 60,70.

Thus, when the drive rod 30 is moved in a proximal fashion toward theuser,the drive cable 50 is similarly pulled in a proximal direction.This drive cable 50 is capable of pulling the rod end 101 so that it tomoves in a proximal direction. Because the jaw links 80 are connected tothe rod end 101 at the pair of pivoting points 103, the jaw links 80 aresimilarly pulled in a proximal direction. In this manner, the jaw links80 rotate from an outwardly flared position to an inwardly flaredposition with respect to the longitudinal axis of the drive rod 30. Whenthis occurs, the jaw links 80 at their distal ends rotate the proximalends of the end effectors 60, 70 toward the longitudinal axis of theinstrument. The end effectors 60, 70 are pivoted at points 64,74 aboutshoulder screw 90 attached to pivot holes 44 contained at the end of theclevis 40. Thus, the end effectors 60, 70 similarly rotate about theclevis 40 so that the entire mechanism is "closed".

On the other hand, when the drive rod 30 is pushed distally, the rod end101 causes the jaw links 80 to flare outwardly from the longitudinalaxis of the drive rod 30. This outward flaring causes the ends 66, 76 ofthe end effectors 60, 70 to similarly move outwardly. The end effectors60, 70pivot at points 64, 74 about shoulder screw 90 connected to thepivot holes44 at the end of clevis 40. Thus, with this rotation, the endeffectors 60,70 also pivot so that the device is now "open". In thisfashion, therefore,reciprocal motion of drive rod 30 operates the jaws60, 70 of the mechanism

It is to be understood that the drive rod 30 is capable of moving withrespect to both the articulation tube 20 and the outer tube 10 of themechanism 1. In this fashion, motion of the drive rod 30 is capable ofbeing performed regardless of the relative positioning of either thearticulation tube 20 or the outer tube 10. Thus, the motion of the driverod 30 is capable of causing performance of the end effectors 60, 70 atany rotational position of the mechanism 1.

There is further described at the distal or end effector portion 100 ofthemechanism 1 an articulation function. This articulation is understoodfrom observing motion of the articulation tube 20 in relation to theouter tube10 of the mechanism. The articulation tube 20 is connected bya weld at itsdistal end 22 to the internal chamber 122 of slider elbow120. The outer tube 10 is rigidly connected at its distal end 12 so thatit fits over thesmaller outer circumference 132 contained at theproximal end of fixed elbow 130. The slider elbow 120, therefore, isable to move with respect to the outer tube 10 along the longitudinalaxis of the mechanism 1. (Thiscan be better seen in FIGS. 1 and 4, forinstance. There, the articulation tube 30 has moved distally. Similarly,the slider elbow 120 has been moveddistally by the articulation tube 20.This sliding motion causes the angulation of the end effectors portion100 of the mechanism, and will be further described herein.)

The distal end 124 of the slider elbow 120 is connected by a pin 150 totheproximal end 112 of the elbow link 110. This elbow link 110 isconnected bya similar pin 150 at its opposite or distal end 114 to pivotholes 46 on tabs 146 of clevis 40. Similarly, the clevis 40 is connectedby pin 150 atpivot hole 48 on an opposite tab 148 to the fixed elbow130. With these connections arranged in this fashion, angulation of endeffector portion 100 about the longitudinal axis of the instrument canbe accomplished. Thus, when the articulation tube 20 is moved distally,the slider elbow 120 is also moved distally. This distal movement of theslider elbow 120 causes rotation of the elbow link 110 about theproximal end 112 connectedto slider elbow 120. Such motion similarlycauses motion of the elbow link 110 about distal end 114 connectingelbow link 110 and clevis 40. However,because the clevis 40 is fixed attab 148 to the fixed elbow 130 connected to longitudinal axis of outertube 10, the clevis 40 is caused to rotate about the longitudinal axisof outer tube 10, in the manner of a typical four-bar linkage.

This can be best be seen in FIG. 4, where motion has been accomplished.There, it is seen that the distal motion of the slider elbow 120 hascaused angulation of the clevis 40 about the outer tube 10. Of course,proximal motion of the slider elbow 120 caused by proximal motion of thearticulation tube 20 causes return rotation of the clevis 40 to apositionwhere there is no angulation between the clevis 40 andlongitudinal axis ofthe outer tube 10.

It is mutually desirable to accomplish operation of this mechanism atany angulation of the clevis 40 with respect to the outer tube 10. Thus,it isimportant for the drive rod 30 to be able to move with respect tothe clevis 40 with any angular position of the clevis 40. This isaccomplishedthrough use of the attachment of drive rod 30 to the drivecable 50. Because the drive cable 50 is flexible, it can move along withthe angularpositioning of the clevis 40 in relation to the position ofthe outer tube 10, the articulation tube 20 and the drive rod 30. Thedrive cable 50 is contained in cable sleeve 140 made from a low frictionmaterial such as Teflon^(TM), and therefore motion of the drive cable 50within the clevis 40 is readily accomplished.

Thus, motion of the drive cable 50 can be accomplished at any angularposition of the clevis 40 with respect to the outer tube 10, even at 90°angles, which has heretofore not been possible for any articulating typeendoscopic instruments.

Now that the end effector 100 portion of the mechanism has beendescribed, this mechanism 1 must be understood in conjunction with thecontrol portion of the instrument contained in its handle. It must beremembered that while articulation and operation of the end effectors60, 70 are accomplished, only three portions extend into the handle.That is, only the outer tube 10, the articulation tube 20, and the driverod 30 extend into the handle section of the instrument. Importantly, itis to be noted that the outer tube is connected via its flange 14 to theend cap 240 of the front piece of articulation knob 260 of theinstrument. This can best be seen in FIGS. 3 and 5. The articulationtube 20 is positioned to fit immediately distal the wings 252 of wingnut 250, better seen in FIG. 3, so that motion of wing nut 250 causesmotion of tube 20. The drive tube 30extends through the entire mechanismand is connected at its proximalmost end to the drive ball 310, which ismaintained within the trigger 350 contained at the proximal end of theinstrument 1. This drive ball 310 is held by set screw 320 into trigger350.

The trigger 350 is capable of rotating about the handle 360 of theinstrument via a pin 330 which connects both the handle and the triggeratpivot holes 352, 362. This pin 330 is held in place by a trigger cover340 as better seen in FIG. 3. Thus, it will be readily understood thatthe driving of the end effectors 60, 70 of this instrument isaccomplished solely by the scissoring action of the handle 360 withrespect to the trigger 350. When the trigger 350 is rotated so that itis closer to the handle 360, the drive ball 310 is caused to pivotproximally with respect to the handle 360. This proximal motion of thedrive ball 310 causes proximal motion of drive rod 30, and consequentlycauses a closing of the end effectors 60, 70 one on the other. Thus, onemay accomplish grasping or scissoring, or any other desired endoscopicfunction. The motion of thetrigger 350 away from the handle 360 causespivoting about pin 330 so that there is caused a distal motion of thedrive rod 30. In this way, this causes a distal motion at the distal end32 of the drive rod 30, causing the end effector jaws 60, 70 to moveaway from one another, and therefore accomplish opening of a scissors orgraspers or any other endoscopic end effectors.

This driving capability of the mechanism 1 must now be understood inconjunction with the articulation or angulation described above, takenfurther in conjunction with rotation of this instrument. First, thearticulation aspects of this instrument will be described. Articulationisaccomplished by the articulation knob assembly, which comprises theend cap240, the front articulation knob 260 and the rear articulationknob 270. Held within this articulation knob assembly is an articulationwing nut 250, fitted within slot 164 of the double slotted tube 160.Slotted tube 160 is screwed at threads 162 to cap 240. This mechanism isarranged so that the double slotted tube 160 holds the articulation wingnut 250 assembly securely. A spring 230 regulates motion of thearticulation wing nut 250 between end cap 240 and slot 164. Thisarticulation wing nut 250 is in turn connected to the articulation drivetube 20, which allows it tointeract with the end effectors 60, 70 andclevis 40 at of the distal end of the mechanism. Of course, because theouter tube 10 is also connected at flange 14 to the articulation end cap240, when articulation is accomplished, the articulation tube 20 iscapable of moving with respect to the outer tube 10.

When it is desired to perform articulation, the user rotates thearticulation knob assembly. In this way, the inner helical threads 262of the front articulation knob 260 cause a relative motion between wings252 of the articulation wing nut 250 and the remainder of theinstrument. In other words, with a counterclockwise motion, thearticulation wing nut 250is pulled proximally toward the user within thecenter 264 of knob 260. In this way, the articulation tube 20 similarlymoves proximally, and therefore sliding elbow 120 is also movedproximally. This tends to straighten the clevis 40 with respect to thelongitudinal axis of the shaft of the mechanism. Conversely, when theknobs 260, 270 are moved clockwise, the helical portion 262 of knob 260causes the articulating wing nut 250 to move distally within slot 164.This distal motion causes distal motion of the slider elbow 120, and inturn causes angulation of the clevis 40 with respect to the longitudinalaxis of the shaft.

Helix 262 converts the rotary motion of the knobs 260, 270 into linearmotion of the articulation tube 20. This rotary motion gives a generallyone-to-one ratio between motion and articulation. Thus, roughly 120° ofknob rotation is needed for 90° of shaft articulation. Thus, the user isable to get a general "feel" for angulation of clevis 40 over arelatively easy (from the user's perspective) length of motion.

Next, it will be necessary to describe rotational motion of thisinstrument. However, in order to do so, it will first be necessary tounderstand the interrelationship between the articulation portion of theinstrument and the rotational portion of the instrument. Generally, ascanbe seen from the figures, rotation spring 220 causes the rotationknob 290 to be moved proximally within the instrument. This rotationknob 290 has contained within it a series of locking ratchets 292. Theselocking ratchets 292 mate with the ratchets 302 of rotational lock 300.The rotational lock 300 is contained in opening 364 in the handle 360and is maintained therein in a fixed position by retaining ring 200placed over distal end 182 of tube 180, over which lock 300 is held.Thus, when the rotation spring 220 pushes on the rotation knob, itcauses the flanges on the rotation knob 290 to mate with the rotationlock ratchets 302, so thatthe rotation knob 290 is statically placedwithin the handle 360. Thus, typically when the user rotatesarticulation knobs 260, 270, these articulation knobs 260, 270 are ableto be rotated independent of rotationof the rotation knob 290. Thiscauses motion of the articulation wing 250 and its concomitantarticulation tube 20 with respect to the entire mechanism, including thestationary outer tube 10 and the stationary handle 360, trigger 350 androtation knob 290 assembly contained therein.

Held within the distal opening 294 of rotation knob 290 is articulationratchet lock 280. This articulation ratchet lock 280 contains a seriesof knurls 282 which are capable of interacting with the knurls 272contained in the proximal portion 274 of the rear articulation knob 270.Further held within the center of rotation knob 290 is tube 180. Thistube 180 is fixedly placed within fixed handle 360. It is held thereinby retaining ring 200. It will be noticed that the tube 180 has attachedto it a flange182 upon which is held the rotation lock 300, as abovedescribed. The rotation lock 300 is held between the flange 182 and theretaining ring 200. The tube 180 has threads 184 on its distal end whichare matedly threaded within the threads of the slotted tube 160 heldwithin the articulating knobs 260, 270. Thus, the articulating knobs260, 270 are free to rotate about the handle 360 and therefore, thearticulation wing 250 moves with respect to the handle 360/trigger 350combination. The drive tube 30 is extended through the center 186 of theapproximately 10 mm tube 180 and into the handle 360 as previouslydescribed.

An articulation spring 210 is placed between articulation ratchet lock280 and spring retainer 170 which is held in place by snap ring 190 onslottedtube 160. This assembly is placed within distal opening 294 ofthe rotationknob on the proximal side of the articulation ratchet lock280. Thus, the rotation spring 220 is able to place a distal force onthe articulation ratchet lock 280. However, because this rotation spring220 has a lower spring force than the more stiffer articulation spring210, the free floating articulation ratchet lock 280 is generally placedin a position proximally displaced from the rear articulation knob 270.Thus, the rotation spring 220 also places a proximal force on therotation knob 290 so that knob 290 is engaged with the rotation ratchetlock 300. The articulation spring 210 is held in place over distal ends168 of tube 160 by spring retainer 170 held over slotted tube 160 byretainer rings 190.

When it is desired to rotate the tubes 10, 20, 30 with respect to thehandle 360, the user needs to place a distal force on the rotationalknob 290. Articulating ratchet lock 280 now contacts the articulationknob 270.Thus, the rotation knob 290 now engages the slotted tube 160 sothat slotted tube 160 transmits rotation to helical thread 262 of thefront articulation knob 260, which now engage the wings 252 of thearticulation wing nut 250 in a rotational sense only, and notlongitudinally, so that the articulation tube is also effectively"locked" in place with respect to the longitudinal position of thearticulation knobs 260, 270. Thus, thedistal motion of the rotation knob290 causes a "locking-up" of the entire rotational mechanism. In thisway, rotation of the rotational knob 290 causes rotation of thearticulation knobs 260, 270, which in turn causes rotation of the outertube 10 as well as the articulation tube 20. This rotation furthercauses simultaneous rotation of the fixed elbow 130, as well as theclevis 40. Thus, the rotational position of the jaws 60, 70 isnoweffected.

Because the jaws are connected via the drive cable 50 to the drive rod30, this causes rotation of the drive rod 30 within the entiremechanism. (Normally, it is to be remembered that the drive rod 30 movesindependently of the articulation tube 20 and the outer tube 10.)Rotationof the drive tube 30 causes rotation of the ball 310 within thehandle 360.Thus, orientation of the drive rod 30 now is effected withinthe handle 360. However, as the trigger 350 is able to cause motion ofthe drive rod 30 at any rotational position of the drive rod 30, utilityof the handle 360/trigger 350 combination is not effected.

Of course, as previously explained, there is also the possibility ofarticulation of the instrument when the articulation knobs 260, 270 arenot held in contact with the rotational knob 290.

With all of the functional capabilities of this mechanism now adequatelydescribed, this device has been described in connection with aparticularly preferred embodiment. It is to be realized that theequivalents of this invention are intended to be covered, and suchinvention and its equivalents are to be derived from the appendedclaims.

We claim:
 1. An endoscopic mechanism comprising:an endoscopic portioncontaining an outer tube which defines a longitudinal axis of said tubeand through which may be operated an drive rod; a drive rod containedwithin said outer tube, said drive rod containing a proximal endconnected to a handle, and a distal end connected to an end effectorportion; a trigger connected to said drive rod said trigger capable ofoperating said end effector portion; and wherein said end effectorportion is capable of being angulated up to 90° with said outer tube;and wherein said end effector portion is connected to an articulationtube concentric to said outer tube, and said articulation tube capableof moving said end effector portion with respect to said longitudinalaxis.
 2. The mechanism of claim 1 further including means attached tosaid handle for rotating said outer tube about said longitudinal axis.3. The mechanism of claim 1 wherein said drive rod is connected to adrive cable at said end effector portion, said cable capable ofoperating at any position of said end effector portion.
 4. The mechanismof claim 1 wherein said articulation tube is connected in said handle toan articulation knob.
 5. The mechanism of claim 4 wherein said endeffector portion is capable of rotating about said longitudinal axis. 6.The mechanism of claim 5 wherein said end effector portion is connectedto said outer tube, and said outer tube is manipulable within saidhandle by a rotation knob.
 7. The mechanism of claim 6 wherein saidrotation knob is matable with said articulation knob, such that saidrotation knob is capable of rotating said outer tube only when saidouter tube is in contact with said articulation knob.
 8. A mechanism forperforming endoscopic procedures comprising:an outer tube having ahollow interior and defining a longitudinal axis; an end effectorportion connected to said hollow outer tube, said end effector portionpivotable about said tube; an articulation mechanism connected to saidend effector portion, said articulation mechanism reciprocable withrespect to said longitudinal axis; and a handle portion attached to saidarticulation mechanism, said handle portion containing an articulationknob capable of reciprocating said articulation tube; and wherein saidarticulation knob contains a helical interior, and said articulationtube is connected to a winged nut within said helical interior, suchthat rotation of said articulation knob causes said winged nut toreciprocate said articulation tube with respect to said longitudinalaxis.
 9. The mechanism of claim 8 wherein said articulation knob iscapable of causing said end effector portion of pivoting up to 90° aboutsaid outer tube.
 10. The handle of an endoscopic instrument containing ashaft and wherein said handle is connected to one knob capable ofcausing said instrument to perform one function, and a second knobcapable of causing said instrument of performing a second function, saidhandle further containing a spring mechanism separating said knobs;andwherein said second knob requires a force to be applied by the userto overcome the spring force of said spring force causes engagement ofsaid first knob and said second knob and said engagement of said knobsallows said second knob to cause said second function.
 11. The handle ofclaim 10 wherein said engagement prevents said first knob to cause saidfirst function.
 12. The handle of claim 10 wherein said first knob is anarticulation knob, and said first function is articulation of saidinstrument shaft.
 13. The handle of claim 10 wherein said second knob isa rotational knob, and said second function is rotation of said shaft.14. The handle of claim 10 wherein said knobs each contain knurls whichinterengage one another during said engagement.
 15. The handle of claim10 wherein said second knob is rigid by said spring force to a lockedportion with said handle when said knobs are not engaged.